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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"`moduleResolution: bundler` diverges from bundlers following node semantics in regards to `default` import","articleBody":"# Bug Report\r\n\r\n### 🔎 Search Terms\r\n\r\nmoduleResolution bundler node webpack default namespace\r\n\r\n### 🕗 Version \u0026 Regression Information\r\n\r\n- This is the behavior in every version I tried: 5.0.4 (the only one with `moduleResolution: bundler`\r\n\r\n### ⏯ Playground Link\r\n\r\nRepro case can be found [here](https://github.com/Andarist/import-reexporting-cjs-bundlers/commit/c41f9256cf3153107226664456f667672fcd64ae)\r\n\r\n### 🙁 Actual behavior\r\n\r\nWhen resolving a `.d.mts` file that proxies to `.d.ts` in a CJS package with `moduleResolution: bundler`, TypeScript complains with an error like:\r\n\u003e `Property 'default' does not exist on type 'string'.ts(2339)`\r\n\r\nThe reason that it complains about it is that TypeScript is resolving `default` import as if the `.d.ts` in this CJS package could export the \"real\" default export. webpack actually follows semantics coined by node and it loads the **namespace** object as the `default` export of that \"cjs file\".\r\n\r\nSo the type-level reality diverges there from runtime. At runtime, with webpack - it works exactly like it would work in node. TypeScript thinks that the intention was to load `module.exports.default` there though.\r\n\r\n### 🙂 Expected behavior\r\n\r\nI'm not exactly sure what's the expected behavior here because \"resolving\" like a bundler is quite under-specified and bundlers are not quite consistent when it comes to this. Even when we check this very same repro, we can see that I had to use `defaultIsModuleExports: true` in Rollup for it to behave the same. By default, Rollup behaves in the same way as TypeScript does.\r\n\r\ncc @andrewbranch \r\n\r\n","author":{"url":"https://github.com/Andarist","@type":"Person","name":"Andarist"},"datePublished":"2023-05-02T18:13:57.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":11},"url":"https://github.com/54102/TypeScript/issues/54102"}